package arithmetic.leetCode.yi;

/**
 * Created with IntelliJ IDEA.
 * Description:
 * User: yilin
 * Date: 2019-07-16
 * Time: 13:51
 */
public class SortConvertList {

    public static class ListNode {
        int val;
        ListNode next;

        ListNode(int x) {
            val = x;
        }


    }

    public static void main(String[] args) {
        ListNode l1 = new ListNode(1);
        l1.next = new ListNode(2);
        l1.next.next = new ListNode(4);
        ListNode l2 = new ListNode(1);
        l2.next = new ListNode(3);
        l2.next.next = new ListNode(4);
        ListNode result = mergeTwoLists(l1, l2);
        while (result != null) {
            System.out.print(result.val);
            result = result.next;
        }
    }

    public static ListNode mergeTwoLists(ListNode l1, ListNode l2) {
        if (l1 == null && l2 == null) return null;
        if (l1 == null) return l2;
        if (l2 == null) return l1;
        ListNode head = null;
        if (l1.val < l2.val) {
            head = l1;
            head.next = mergeTwoLists(head.next, l2);
        } else {
            head = l2;
            head.next = mergeTwoLists(l1, head.next);
        }
        return head;
    }
}
